God help us, when will it ever stop? Is there no organ, no medical condition, no tiny part of the human body that is not helped by exercise?
A new mouse study in the The Journal of Neuroscience finds that exercise appears to be good for the retina, and may even slow the development of age-related macular degeneration, which is estimated to affect nearly 2 million older Americans. The key appears to be a helpful protein called brain-derived neurotrophic factor. From the press release:
Moderate aerobic exercise helps to preserve the structure and function of nerve cells in the retina after damage, according to an animal study appearing February 12 in The Journal of Neuroscience. The findings suggest exercise may be able to slow the progression of retinal degenerative diseases.
Age-related macular degeneration, one of the leading causes of blindness in the elderly, is caused by the death of light-sensing nerve cells in the retina called photoreceptors. Although several studies in animals and humans point to the protective effects of exercise in neurodegenerative diseases or injury, less is known about how exercise affects vision.
Machelle Pardue, PhD, together with her colleagues Eric Lawson and Jeffrey H. Boatright, PhD, at the Atlanta VA Center for Visual and Neurocognitive Rehabilitation and Emory University, ran mice on a treadmill for two weeks before and after exposing the animals to bright light that causes retinal degeneration. The researchers found that treadmill training preserved photoreceptors and retinal cell function in the mice.
“This is the first report of simple exercise having a direct effect on retinal health and vision,” Pardue said. “This research may one day lead to tailored exercise regimens or combination therapies in treatments of blinding diseases.”
In the current study, the scientists trained mice to run on a treadmill for one hour per day, five days per week, for two weeks. After the animals were exposed to toxic bright light — a commonly used model of retinal degeneration — they exercised for two more weeks. The exercised animals lost only half the number of photoreceptor cells as animals that spent the equivalent amount of time on a stationary treadmill.
The study comes out Feb. 12 in The Journal Of Neuroscience, and we'll add a link when it's up. A bit more from the release:
“These findings further our current understanding of the neuroprotective effects of aerobic exercise and the role of BDNF,” explained Michelle Ploughman, PhD, who studies the effects of exercise on the healthy and diseased brain at Memorial University of Newfoundland, and was not involved with this study. “People who are at risk of macular degeneration or have early signs of the disease may be able to slow down the progression of visual impairment,” she added.
On Reddit, a commenter offers this pithy quote:
I know this comment will sound trite, but guys, moderate aerobic exercise basically helps everything. Exercise is the nearest thing we have to a preventative or palliative for everything that can ever go wrong with you.
You should exercise.